AB0441 PREDICTORS OF CLASI RESPONSE OVER TIME IN A MULTICENTRIC REAL LIFE COHORT OF SLE PATIENTS TREATED WITH BELIMUMAB
Authors: M. Gatto, R. Depascale, A. Tincani, G. Emmi, S. Scarpato, F. Conti, M. Govoni, M. Mosca, M. Gerosa, E. Bozzolo, V. Canti, A. Gabrielli, E. Gremese, S. De Vita, F. Ciccia, C. Salvarani, M. Rossini, P. Faggioli, A. Laria, A. De Paulis, R. Gerli, E. Brunetta, A. Mathieu, C. Selmi, R. De Angelis, S. Negrini, M. Zen, A. Doria, L. Iaccarino
Journal: Annals of the Rheumatic Diseases (2022)

Background Over 80% of patients affected with SLE experience skin involvement. The anti-BLyS drug belimumab was shown effective in ameliorating mucocutaneous SLE manifestations in clinical trials and real-life studies. Cutaneous response is quantified through the CLASI (cutaneous lupus erythematosus area and severity index). Clinically relevant improvements are defined as decreases of ≥50% (CLASI50) or 70% (CLASI70) from baseline values. Objectives To assess rates and predictors of CLASI50 and CLASI70 in the Berliss multicentric SLE cohort 1 of patients treated with belimumab. Methods Baseline and ongoing features of patients with baseline active skin involvement (CLASI&gt;0) were assessed in relationship to the chosen outcomes CLASI50 and CLASI70 at 24 and 52 weeks. A subanalysis on patients with CLASI≥5 was as well conducted. Logistic regression was employed to identify predictors of response. Results 172 patients displayed skin involvement at baseline (CLASI&gt;0). Of those, 124 displayed at least a 12-month-follow-up and were included in the analysis. Seventy-seven (62.1%) patients reached CLASI50 at 24 weeks and 91 (77.8%) at 52 weeks; 87 (70.2%) reached CLASI70 at 24 and 99 (79.8%) at 52 weeks. Baseline predictors of CLASI50 at 24 weeks were CLASI-damage (CLASI-d) (OR [95%CI], p; 0.79 [0.65-0.98] 0.03) and disease duration (0.93[0.86-0.99], 0.011). No baseline predictors of CLASI70 at 24 weeks emerged, however having achieved a CLASI50 response at 24 weeks portended CLASI50 and 70 response through week 52 (p&lt;0.01, Table 1). In the subgroup of patients with CLASI≥5, longer disease and increased CLASI-d at baseline confirmed as negative predictors of CLASI50 at 24 weeks. In this subset, use of antimalarials and active smoking at baseline predicted CLASI70 at 24 weeks (Table 1). Table 1. Predictors of CLASI-A Response at Week 24 and 52 by Baseline CLASI-A at 50% and 70% Response Thresholds Timepoint Outcome Variable OR[95%CI] p CLASI&gt;0 24 weeks CLASI50 CLASI-d 0.79 [0.65-0.98] 0.030 Disease duration 0.93[0.86-0.99], 0.011 CLASI70 CLASI-d 0.93 [0.74-1.16], 0.51 Disease duration 0.97 [0.97-1.02], 0.18 52 weeks CLASI50 CLASI50 at 24 weeks 14.3[4.88-44.42], &lt;0.001 CLASI70 CLASI50 at 24 weeks 6.22 [2.00-19.34], 0.002 CLASI≥5 24 weeks CLASI50 CLASI-d 0.72 [0.53-0.98], 0.037 Disease duration 0.93 [0.66-1.00], 0.071 CLASI70 Antimalarials 6.61 [1.20-36.29] 0.032 Smoking 0.15 [0.03-0.83], 0.034 52 weeks CLASI50 CLASI50 at 24 weeks 22.0 [2.47-196.05], 0.006 CLASI70 CLASI50 at 24 weeks 1.24 [0.06-25.08], 0.88 CLASI, cutaneous lupus erythematosus area and severity index; CLASI-d, CLASI damage; CLASI50 and CLASI70: decrease ≥50% or ≥70% in CLASI from baseline. OR and 95%CIs are estimated using a logistic regression model with stratification factors as covariates (SLEDAI-2K at baseline, baseline prednisone dosage). Conclusion Earlier use of belimumab favors achievement of skin response among SLE patients and attainment of a prompt response predicts further response. Use of antimalarials reinforces while smoking hampers a more profound CLASI improvement over time. References: [1]Gatto M, et al. Arthritis Rheumatol. 2020 Aug;72(8):1314-1324 Disclosure of Interests Mariele Gatto Speakers bureau: GSK, Grant/research support from: GSK, Roberto Depascale: None declared, Angela Tincani: None declared, Giacomo Emmi: None declared, Salvatore Scarpato: None declared, Fabrizio Conti: None declared, Marcello Govoni: None declared, Marta Mosca: None declared, Maria Gerosa: None declared, Enrica Bozzolo: None declared, Valentina Canti: None declared, Armando Gabrielli: None declared, Elisa Gremese: None declared, Salvatore De Vita: None declared, francesco ciccia: None declared, Carlo Salvarani: None declared, Maurizio Rossini: None declared, Paola Faggioli: None declared, Antonella Laria: None declared, Amato De Paulis: None declared, Roberto Gerli: None declared, Enrico Brunetta: None declared, Alessandro Mathieu: None declared, Carlo Selmi: None declared, Rossella De Angelis: None declared, Simone Negrini: None declared, Margherita Zen: None declared, Andrea Doria Speakers bureau: GSK, Eli Lilly, Roche, Grant/research support from: GSK, Luca Iaccarino Speakers bureau: GSK, Grant/research support from: GSK